/*	$OpenBSD: lexi.c,v 1.18 2015/01/22 05:35:27 jsg Exp $	*/

/*
 * Copyright (c) 1980, 1993
 *	The Regents of the University of California.
 * Copyright (c) 1976 Board of Trustees of the University of Illinois.
 * Copyright (c) 1985 Sun Microsystems, Inc.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * Here we have the token scanner for indent.  It scans off one token and puts
 * it in the global variable "token".  It returns a code, indicating the type
 * of token scanned.
 */

#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <err.h>
#include "indent_globs.h"
#include "indent_codes.h"

#define alphanum 1
#define opchar 3

struct templ {
    char       *rwd;
    int         rwcode;
};

struct templ specialsinit[] = {
	{ "switch", 1 },
	{ "case", 2 },
	{ "break", 0 },
	{ "struct", 3 },
	{ "union", 3 },
	{ "enum", 3 },
	{ "default", 2 },
	{ "int", 4 },
	{ "char", 4 },
	{ "float", 4 },
	{ "double", 4 },
	{ "long", 4 },
	{ "short", 4 },
	{ "typdef", 4 },
	{ "unsigned", 4 },
	{ "register", 4 },
	{ "static", 4 },
	{ "global", 4 },
	{ "extern", 4 },
	{ "void", 4 },
	{ "goto", 0 },
	{ "return", 0 },
	{ "if", 5 },
	{ "while", 5 },
	{ "for", 5 },
	{ "else", 6 },
	{ "do", 6 },
	{ "sizeof", 7 },
};

struct templ *specials = specialsinit;
int	nspecials = sizeof(specialsinit) / sizeof(specialsinit[0]);
int	maxspecials;

char        chartype[128] =
{				/* this is used to facilitate the decision of
				 * what type (alphanumeric, operator) each
				 * character is */
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0,
    0, 3, 0, 0, 1, 3, 3, 0,
    0, 0, 3, 3, 0, 3, 0, 3,
    1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 0, 0, 3, 3, 3, 3,
    0, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 0, 0, 0, 3, 1,
    0, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 1, 1, 1, 1, 1,
    1, 1, 1, 0, 3, 0, 3, 0
};




int
lexi(void)
{
    int         unary_delim;	/* this is set to 1 if the current token
				 * forces a following operator to be unary */
    static int  last_code;	/* the last token type returned */
    static int  l_struct;	/* set to 1 if the last token was 'struct' */
    int         code;		/* internal code to be returned */
    char        qchar;		/* the delimiter character for a string */
    int		i;

    e_token = s_token;		/* point to start of place to save token */
    unary_delim = false;
    ps.col_1 = ps.last_nl;	/* tell world that this token started in
				 * column 1 iff the last thing scanned was nl */
    ps.last_nl = false;

    while (*buf_ptr == ' ' || *buf_ptr == '\t') {	/* get rid of blanks */
	ps.col_1 = false;	/* leading blanks imply token is not in column
				 * 1 */
	if (++buf_ptr >= buf_end)
	    fill_buffer();
    }

    /* Scan an alphanumeric token */
    if (chartype[(int)*buf_ptr] == alphanum ||
	(buf_ptr[0] == '.' && isdigit((unsigned char)buf_ptr[1]))) {
	/*
	 * we have a character or number
	 */
	char *j;	/* used for searching thru list of
			 * reserved words */
	if (isdigit((unsigned char)*buf_ptr) ||
	    (buf_ptr[0] == '.' && isdigit((unsigned char)buf_ptr[1]))) {
	    int         seendot = 0,
	                seenexp = 0,
			seensfx = 0;
	    if (*buf_ptr == '0' &&
		    (buf_ptr[1] == 'x' || buf_ptr[1] == 'X')) {
		*e_token++ = *buf_ptr++;
		*e_token++ = *buf_ptr++;
		while (isxdigit(*buf_ptr)) {
		    CHECK_SIZE_TOKEN;
		    *e_token++ = *buf_ptr++;
		}
	    }
	    else
		while (1) {
		    if (*buf_ptr == '.') {
			if (seendot)
			    break;
			else
			    seendot++;
		    }
		    CHECK_SIZE_TOKEN;
		    *e_token++ = *buf_ptr++;
		    if (!isdigit((unsigned char)*buf_ptr) && *buf_ptr != '.') {
			if ((*buf_ptr != 'E' && *buf_ptr != 'e') || seenexp)
			    break;
			else {
			    seenexp++;
			    seendot++;
			    CHECK_SIZE_TOKEN;
			    *e_token++ = *buf_ptr++;
			    if (*buf_ptr == '+' || *buf_ptr == '-')
				*e_token++ = *buf_ptr++;
			}
		    }
		}
	    while (1) {
		if (!(seensfx & 1) &&
			(*buf_ptr == 'U' || *buf_ptr == 'u')) {
		    CHECK_SIZE_TOKEN;
		    *e_token++ = *buf_ptr++;
		    seensfx |= 1;
		    continue;
		}
        	if (!(seensfx & 2) &&
			(*buf_ptr == 'L' || *buf_ptr == 'l')) {
		    CHECK_SIZE_TOKEN;
		    if (buf_ptr[1] == buf_ptr[0])
		        *e_token++ = *buf_ptr++;
		    *e_token++ = *buf_ptr++;
		    seensfx |= 2;
		    continue;
		}
		break;
	    }
	    if (!(seensfx & 1) &&    
	        (*buf_ptr == 'F' || *buf_ptr == 'f')) {
		CHECK_SIZE_TOKEN;
		*e_token++ = *buf_ptr++;
		seensfx |= 1;
	    }
	}
	else
	    while (chartype[(int)*buf_ptr] == alphanum) {	/* copy it over */
		CHECK_SIZE_TOKEN;
		*e_token++ = *buf_ptr++;
		if (buf_ptr >= buf_end)
		    fill_buffer();
	    }
	*e_token++ = '\0';
	while (*buf_ptr == ' ' || *buf_ptr == '\t') {	/* get rid of blanks */
	    if (++buf_ptr >= buf_end)
		fill_buffer();
	}
	ps.its_a_keyword = false;
	ps.sizeof_keyword = false;
	if (l_struct) {		/* if last token was 'struct', then this token
				 * should be treated as a declaration */
	    l_struct = false;
	    last_code = ident;
	    ps.last_u_d = true;
	    return (decl);
	}
	ps.last_u_d = false;	/* Operator after identifier is binary */
	last_code = ident;	/* Remember that this is the code we will
				 * return */

	/*
	 * This loop will check if the token is a keyword.
	 */
	for (i = 0; i < nspecials; i++) {
	    char *p = s_token;	/* point at scanned token */
	    j = specials[i].rwd;
	    if (*j++ != *p++ || *j++ != *p++)
		continue;	/* This test depends on the fact that
				 * identifiers are always at least 1 character
				 * long (ie. the first two bytes of the
				 * identifier are always meaningful) */
	    if (p[-1] == 0)
		break;		/* If its a one-character identifier */
	    while (*p++ == *j)
		if (*j++ == 0)
		    goto found_keyword;	/* I wish that C had a multi-level
					 * break... */
	}
	if (i < nspecials) {		/* we have a keyword */
    found_keyword:
	    ps.its_a_keyword = true;
	    ps.last_u_d = true;
	    switch (specials[i].rwcode) {
	    case 1:		/* it is a switch */
		return (swstmt);
	    case 2:		/* a case or default */
		return (casestmt);

	    case 3:		/* a "struct" */
		if (ps.p_l_follow)
		    break;	/* inside parens: cast */
		l_struct = true;

		/*
		 * Next time around, we will want to know that we have had a
		 * 'struct'
		 */
	    case 4:		/* one of the declaration keywords */
		if (ps.p_l_follow) {
		    ps.cast_mask |= 1 << ps.p_l_follow;
		    break;	/* inside parens: cast */
		}
		last_code = decl;
		return (decl);

	    case 5:		/* if, while, for */
		return (sp_paren);

	    case 6:		/* do, else */
		return (sp_nparen);

	    case 7:
		ps.sizeof_keyword = true;
	    default:		/* all others are treated like any other
				 * identifier */
		return (ident);
	    }			/* end of switch */
	}			/* end of if (found_it) */
	if (*buf_ptr == '(' && ps.tos <= 1 && ps.ind_level == 0) {
	    char *tp = buf_ptr;
	    while (tp < buf_end)
		if (*tp++ == ')' && (*tp == ';' || *tp == ','))
		    goto not_proc;
	    strlcpy(ps.procname, token, sizeof ps.procname);
	    ps.in_parameter_declaration = 1;
	    rparen_count = 1;
    not_proc:;
	}
	/*
	 * The following hack attempts to guess whether or not the current
	 * token is in fact a declaration keyword -- one that has been
	 * typedefd
	 */
	if (((*buf_ptr == '*' && buf_ptr[1] != '=') ||
	    isalpha((unsigned char)*buf_ptr) || *buf_ptr == '_')
		&& !ps.p_l_follow
	        && !ps.block_init
		&& (ps.last_token == rparen || ps.last_token == semicolon ||
		    ps.last_token == decl ||
		    ps.last_token == lbrace || ps.last_token == rbrace)) {
	    ps.its_a_keyword = true;
	    ps.last_u_d = true;
	    last_code = decl;
	    return decl;
	}
	if (last_code == decl)	/* if this is a declared variable, then
				 * following sign is unary */
	    ps.last_u_d = true;	/* will make "int a -1" work */
	last_code = ident;
	return (ident);		/* the ident is not in the list */
    }				/* end of procesing for alpanum character */

    /* Scan a non-alphanumeric token */

    *e_token++ = *buf_ptr;		/* if it is only a one-character token, it is
				 * moved here */
    *e_token = '\0';
    if (++buf_ptr >= buf_end)
	fill_buffer();

    switch (*token) {
    case '\n':
	unary_delim = ps.last_u_d;
	ps.last_nl = true;	/* remember that we just had a newline */
	code = (had_eof ? 0 : newline);

	/*
	 * if data has been exausted, the newline is a dummy, and we should
	 * return code to stop
	 */
	break;

    case '\'':			/* start of quoted character */
    case '"':			/* start of string */
	qchar = *token;
	if (troff) {
	    e_token[-1] = '`';
	    if (qchar == '"')
		*e_token++ = '`';
	    e_token = chfont(&bodyf, &stringf, e_token);
	}
	do {			/* copy the string */
	    while (1) {		/* move one character or [/<char>]<char> */
		if (*buf_ptr == '\n') {
		    printf("%d: Unterminated literal\n", line_no);
		    goto stop_lit;
		}
		CHECK_SIZE_TOKEN;	/* Only have to do this once in this loop,
					 * since CHECK_SIZE guarantees that there
					 * are at least 5 entries left */
		*e_token = *buf_ptr++;
		if (buf_ptr >= buf_end)
		    fill_buffer();
		if (*e_token == BACKSLASH) {	/* if escape, copy extra char */
		    if (*buf_ptr == '\n')	/* check for escaped newline */
			++line_no;
		    if (troff) {
			*++e_token = BACKSLASH;
			if (*buf_ptr == BACKSLASH)
			    *++e_token = BACKSLASH;
		    }
		    *++e_token = *buf_ptr++;
		    ++e_token;	/* we must increment this again because we
				 * copied two chars */
		    if (buf_ptr >= buf_end)
			fill_buffer();
		}
		else
		    break;	/* we copied one character */
	    }			/* end of while (1) */
	} while (*e_token++ != qchar);
	if (troff) {
	    e_token = chfont(&stringf, &bodyf, e_token - 1);
	    if (qchar == '"')
		*e_token++ = '\'';
	}
stop_lit:
	code = ident;
	break;

    case ('('):
    case ('['):
	unary_delim = true;
	code = lparen;
	break;

    case (')'):
    case (']'):
	code = rparen;
	break;

    case '#':
	unary_delim = ps.last_u_d;
	code = preesc;
	break;

    case '?':
	unary_delim = true;
	code = question;
	break;

    case (':'):
	code = colon;
	unary_delim = true;
	break;

    case (';'):
	unary_delim = true;
	code = semicolon;
	break;

    case ('{'):
	unary_delim = true;

	/*
	 * if (ps.in_or_st) ps.block_init = 1;
	 */
	/* ?	code = ps.block_init ? lparen : lbrace; */
	code = lbrace;
	break;

    case ('}'):
	unary_delim = true;
	/* ?	code = ps.block_init ? rparen : rbrace; */
	code = rbrace;
	break;

    case 014:			/* a form feed */
	unary_delim = ps.last_u_d;
	ps.last_nl = true;	/* remember this so we can set 'ps.col_1'
				 * right */
	code = form_feed;
	break;

    case (','):
	unary_delim = true;
	code = comma;
	break;

    case '.':
	unary_delim = false;
	code = period;
	break;

    case '-':
    case '+':			/* check for -, +, --, ++ */
	code = (ps.last_u_d ? unary_op : binary_op);
	unary_delim = true;

	if (*buf_ptr == token[0]) {
	    /* check for doubled character */
	    *e_token++ = *buf_ptr++;
	    /* buffer overflow will be checked at end of loop */
	    if (last_code == ident || last_code == rparen) {
		code = (ps.last_u_d ? unary_op : postop);
		/* check for following ++ or -- */
		unary_delim = false;
	    }
	}
	else if (*buf_ptr == '=')
	    /* check for operator += */
	    *e_token++ = *buf_ptr++;
	else if (*buf_ptr == '>') {
	    /* check for operator -> */
	    *e_token++ = *buf_ptr++;
	    if (!pointer_as_binop) {
		unary_delim = false;
		code = unary_op;
		ps.want_blank = false;
	    }
	}
	break;			/* buffer overflow will be checked at end of
				 * switch */

    case '=':
	if (ps.in_or_st)
	    ps.block_init = 1;
#ifdef undef
	if (chartype[*buf_ptr] == opchar) {	/* we have two char assignment */
	    e_token[-1] = *buf_ptr++;
	    if ((e_token[-1] == '<' || e_token[-1] == '>') && e_token[-1] == *buf_ptr)
		*e_token++ = *buf_ptr++;
	    *e_token++ = '=';	/* Flip =+ to += */
	    *e_token = 0;
	}
#else
	if (*buf_ptr == '=') {/* == */
	    *e_token++ = '=';	/* Flip =+ to += */
	    buf_ptr++;
	    *e_token = 0;
	}
#endif
	code = binary_op;
	unary_delim = true;
	break;
	/* can drop thru!!! */

    case '>':
    case '<':
    case '!':			/* ops like <, <<, <=, !=, etc */
	if (*buf_ptr == '>' || *buf_ptr == '<' || *buf_ptr == '=') {
	    *e_token++ = *buf_ptr;
	    if (++buf_ptr >= buf_end)
		fill_buffer();
	}
	if (*buf_ptr == '=')
	    *e_token++ = *buf_ptr++;
	code = (ps.last_u_d ? unary_op : binary_op);
	unary_delim = true;
	break;

    default:
	if (token[0] == '/' && *buf_ptr == '*') {
	    /* it is start of comment */
	    *e_token++ = '*';

	    if (++buf_ptr >= buf_end)
		fill_buffer();

	    code = comment;
	    unary_delim = ps.last_u_d;
	    break;
	}
	while (*(e_token - 1) == *buf_ptr || *buf_ptr == '=') {
	    /*
	     * handle ||, &&, etc, and also things as in int *****i
	     */
	    *e_token++ = *buf_ptr;
	    if (++buf_ptr >= buf_end)
		fill_buffer();
	}
	code = (ps.last_u_d ? unary_op : binary_op);
	unary_delim = true;


    }				/* end of switch */
    if (code != newline) {
	l_struct = false;
	last_code = code;
    }
    if (buf_ptr >= buf_end)	/* check for input buffer empty */
	fill_buffer();
    ps.last_u_d = unary_delim;
    *e_token = '\0';		/* null terminate the token */
    return (code);
}

/*
 * Add the given keyword to the keyword table, using val as the keyword type
 */
void
addkey(char *key, int val)
{
    struct templ *p;
    int i;

    for (i = 0; i < nspecials; i++) {
	p = &specials[i];
	if (p->rwd[0] == key[0] && strcmp(p->rwd, key) == 0)
	    return;
    }

    if (specials == specialsinit) {
	/*
	 * Whoa. Must reallocate special table.
	 */
	nspecials = sizeof (specialsinit) / sizeof (specialsinit[0]);
	maxspecials = nspecials + (nspecials >> 2);
	specials = (struct templ *)calloc(maxspecials, sizeof specials[0]);
	if (specials == NULL)
	    err(1, NULL);
	memcpy(specials, specialsinit, sizeof specialsinit);
    } else if (nspecials >= maxspecials) {
	int newspecials = maxspecials + (maxspecials >> 2);
	struct templ *specials2;

	specials2 = reallocarray(specials, newspecials, sizeof(specials[0]));
	if (specials2 == NULL)
	    err(1, NULL);
	specials = specials2;
	maxspecials = newspecials;
    }

    p = &specials[nspecials];
    p->rwd = key;
    p->rwcode = val;
    nspecials++;
    return;
}
